Transport Scotland has confirmed it is “exploring” the option of daytime sailings with NorthLink Ferries.
The government agency provided the update to North Isles councillor Ryan Thomson.
Mr Thomson said was an “encouraging response”.
He had raised the issue after photos circulated online showing passengers, including children and older people, sleeping on the floor of a crowded crossing.
The letter from Transport Scotland states: “The suggestion of daytime sailings is one that has been previously been put forward and is an option we are currently exploring with the operator.
“An update will be provided to stakeholders when all of the details are available and we are able to consider fully the effects this proposal would have on the ferry service.”
Mr Thomson had requested three daytime sailings and four evening sailings per week, with additional sailings during the summer months as necessary.
He said the new proposed timetable would allow cabins to be opened up on evening sailings, address capacity issues, and make travel cheaper for islanders and tourists.
“It’s win win,” he said.
“I’m extremely encouraged that dialogue has now been opened up with Serco, and hope that councillors, the SIC and the Shetland community can work with Transport Scotland, the Scottish government and Serco Northlink to find a sustainable, long term solution which meets the needs of our community and our businesses.”